In Pilot's Jargon
, the ceiling is a measure of current visibility
. It is expressed in altitude
, and is the height of the bottom of the lowest cloud strata
present, which (from the ground) would appear to be a 'ceiling.' When the sky
is completely clear, the ceiling is said to be unlimited
When used in the context of particular aircraft, the term refers to the maximum altitude attainable by that aircraft under specified conditions.